This focusing helicoid tube features an M52 front mount and a standard M42 rear mount, constructed from lightweight alloy material. It provides precise focus control for macro photography, especially useful for lenses without a focus ring. By adding extension between the camera body and lens, the helicoid increases the distance between the lens and the sensor plane. This allows the lens to focus much closer than normal. The greater the extension, the closer the minimum focusing distance. When used with a standard lens, this adapter delivers image quality comparable to the original lens performance. It offers excellent size, sharpness, and versatility for macro and close-up photography. Specifications: - Length: 17mm (minimum) to 31mm (maximum) - Provides 14mm of focusing movement - Compatibility: M52 to M42 screw mount lenses and cameras - Color: Black - Material: Metal Package Contents: 1 x M52 to M42 (1731mm) Focusing Helicoid Adapter Note: There is no electronic connection between the camera body and the lens; therefore, autofocus is not available. When using this adapter with a DSLR or SLR camera, set the camera to manual (M) mode. The package includes only the items listed above. Note: Lighting and display differences may cause slight variations in color between the product image and the actual item. Measurement allows an error of +/- 13 cm.